1. Field of Invention
This invention relates to an over-the-road vehicle such as a trailer, wherein a wheel assembly commonly known as a bogie is coupled to the body of the trailer, the coupling between the trailer and the bogie can be adjusted so that the bogie can be shifted with respect to the body to vary the load on the axles in the bogie. Alternatively, the bogie can be removed entirely so that the trailer can be shipped in the form of a containerized cargo unit to be transported by a railcar, ship or other form of vehicle.
2. Description of the Prior Art
The bogie which includes wheels, brakes, a subtrain suspension and other items is attached to the trailer by a positive locking mechanism. This locking mechanism on the bogie generally includes two or more heavy steel pins which secure the bogie in fore and aft directions with respect to the trailer body. The bogie includes a pair of rails which are adapted to slide in a pair of tracks secured to the bottom of the trailer body, which tracks guide the bogie for movement for adjusting the position of the bogie with respect to the longitudinal length of the trailer body.
One form of attaching the bogie to the trailer body is described in the U.S. Pat. No. 4,273,347, wherein the locking pins have a particular configuration and are adapted to function as valves in a mechanical locking system. The pins have a central portion supporting a pair of spaced "O" rings, the central portion communicating with a pair of conduits which are connected to a source of air supply and to an emergency tank connected to the mechanical brake system on the bogie. If the pin is not properly inserted to couple the bogie to the trailer body, the central portion of pin is off-center with respect to the pressure lines and therefore the air supply provided by a tractor hitched to the trailer body will be vented to the atmosphere and will, therefore, not release the mechanical brake system on the bogie. Such pins, and "O" rings acting as movable valve bodies are subject to corrosion and malfunction because of dirt. Also, it requires that the housing supporting the pins be constructed as a cylinder for supporting the movable pins.
The foregoing pins are always biased in an outwardly direction seeking to interlock the rails on the bogie with the tracks on the trailer body. This is achieved by a spring member which is externally located and subject to corrosion as well as breaking. Should such a spring which actuates in tandem a pair of pins break, separation between the bogie and trailer body could readily occur.